r3wp [groups: 83 posts: 189283]
  • Home
  • Script library
  • AltME Archive
  • Mailing list
  • Articles Index
  • Site search
 

World: r3wp

[Red] Red language group

BrianH
28-Feb-2011
[48]
Look at the source of LOAD and sys/load-header for some good examples 
of the CASE/all style. It's worth supporting.
Dockimbel
28-Feb-2011
[49]
I'm sure it would be nice to have it, but my short term goal with 
Red/System is to just code the minimal set of primitives required 
to build the upper layer (Red's runtime layer). I was hoping that 
other developers could keep expanding/improving Red/System while 
I would progress on the Red part.
BrianH
28-Feb-2011
[50]
Good point.
Andreas
28-Feb-2011
[51x2]
What makes CASE/all different from a long sequence of IFs?
(In respect to Red/System, where those will be equal, performance-wise.)
BrianH
28-Feb-2011
[53]
Maintainability of code. We found that the CASE/all style makes changes 
to code easy to make, and control flow easy to understand. This realization 
came out of the process of rewriting R3's module system into easier-to-maintain 
code.
Dockimbel
28-Feb-2011
[54]
It's sleep time here, but I can't resist to post a first Red/System 
source example:

#import [
	"kernel32.dll" [
		GetStdHandle: "GetStdHandle" [
		  	type		[integer!]
		  	return:		[integer!]
		]
		WriteConsole: "WriteConsoleA" [
		  	handle		[integer!]
		  	buffer		[string!]
		  	len		[integer!]
		  	written		[struct! [value [integer!]]]
		  	reserved	[integer!]
		  	return:		[integer!]
		]
	]
]

stdout: GetStdHandle -11
written: struct [value [integer!]]

prin: func [s [string!] return: [integer!]][
	WriteConsole stdout s length? s written 0
]

prin "Hello Red World!"
Andreas
28-Feb-2011
[55]
Ladislav, regarding Red being a REBOL dialect if Red's syntax is 
a subset of the data exchange dialect syntax: I fully agree.
Dockimbel
28-Feb-2011
[56]
Of course, this will be part of Red/System own small runtime, exposing 
among other functions, PRIN and PRINT.
BrianH
28-Feb-2011
[57]
How are the types of local variables declared in Red/System? The 
slideshow says no type inference...
Dockimbel
28-Feb-2011
[58]
As in REBOL: using /LOCAL followed by name and datatype.
BrianH
28-Feb-2011
[59]
And /local is special, not just another refinement?
Dockimbel
28-Feb-2011
[60]
Yes, it's a reserved keyword. I planned to add refinement support 
also, but I'm not sure I will need it to implement Red runtime, so 
it will be probably postponed.
Mchean
28-Feb-2011
[61]
how many attended the conference?
Dockimbel
28-Feb-2011
[62]
We were 5, but it felt like 10 ;-)
Mchean
28-Feb-2011
[63]
heh, well having actually had a conf i think you can use a 3x multiplier
Dockimbel
28-Feb-2011
[64]
Brian: here's an example of /LOCAL usage from my Red/System tests 
scripts (just a variation on the real PRINT function):


print: func [s [string!] return: [integer!] /local lf [string!] sz 
[integer!]][
	lf: "^/"
	prin s
	sz: 1
	WriteConsole stdout lf sz written 0
]
BrianH
28-Feb-2011
[65]
No tmp variables then :)
Dockimbel
28-Feb-2011
[66]
Nope.
Kaj
28-Feb-2011
[67]
Cool examples, Doc
Dockimbel
28-Feb-2011
[68]
The real PRINT is defined as: 

print: func [s [string!]][
	prin s
	prin "^/"
]
BrianH
28-Feb-2011
[69x3]
Only string!, no binary!?
I'm wondering about the Unicode strategy...
In Red/System, I mean. Of course Red will have both.
Dockimbel
28-Feb-2011
[72]
Binary! is half-supported. It was part of my initial list of type 
to support, but as I didn't needed it so far, it's not supported. 
That might change when I'll implement the lexical analyzer.
BrianH
28-Feb-2011
[73]
Have you decided yet whether the lexical analyzer will have the same 
source-is-UTF8-binary strategy as R3?
Dockimbel
28-Feb-2011
[74]
I plan to support UTF-8 scripts for both Red & Red/System. The memory 
storage model is not yet decided, could be UTF-8 or UCS-2.
BrianH
28-Feb-2011
[75]
And arguments and locals can only have one type in their typespecs 
for Red/System?
Dockimbel
28-Feb-2011
[76]
In fact, they can have several types as long as they take the same 
space in memory, but support for that has not yet been implemented.
Andreas
28-Feb-2011
[77]
Do you currently compile the above directly to binary machine code?
Dockimbel
28-Feb-2011
[78]
Yes, machine code, then generating an executable.
Andreas
28-Feb-2011
[79]
ABI differences will probably give you the heebie-jeebies :)
Dockimbel
28-Feb-2011
[80x2]
The whole compiler is 40KB, the linker is 20KB.
I did the PE/COFF support, no other ABI can be so screwed up. :-)
Kaj
28-Feb-2011
[82]
Obviously, GCC is superior at 50 MB or so
Andreas
28-Feb-2011
[83x2]
That is only the binary format :)
I assume you currently do x86 stdcall only?
Dockimbel
28-Feb-2011
[85]
Yes, but the support for cdecl is like adding a couple of lines to 
the current code.
Andreas
28-Feb-2011
[86]
Sure. But that quickly gets extremely annoying :)
Dockimbel
28-Feb-2011
[87]
Red/System uses stdcall for its own functions, I found out that it 
was generating shorter code than cdecl.
BrianH
28-Feb-2011
[88]
That's why stdcall was invented :)
Andreas
28-Feb-2011
[89]
Or on x86, fastcall, rather :)
Dockimbel
28-Feb-2011
[90x2]
The really annoying part was having to reverse the arguments list 
to support stdcall. It's a much more difficult when you're compiling 
in one pass directly to machine code.
Fastcall, sure, that would be the target in a future version with 
an optimizing compiler.
BrianH
28-Feb-2011
[92]
Do string references in Red/System have indexes, or are they just 
pointers?
Dockimbel
28-Feb-2011
[93]
They support indexed read/write accesses like in C, but using a REBOL 
syntax, so s/1, s/2, s/3...
BrianH
28-Feb-2011
[94]
I meant offset references an internal pointer to the head and an 
offset index, like s: next s.
Dockimbel
28-Feb-2011
[95x2]
Indexing with a variable should also be possible: 
s: "hello"
c: 1

s/c or s/:c (haven't decided yet which one is the more appropriate)
Nope, no indexes like in REBOL strings, that's too high-level for 
Red/System.
BrianH
28-Feb-2011
[97]
Going with the latter (s/:c) would be more compatible with REBOL 
and Red, and leave room for expanding Red/System's capabilities in 
the future.